Operating chair



I Oct. 27, 1936. A, J. MAY 2,059,130

OPERATING CHAIR Filed Nov. 14, 1954 3 Sheets-Sheet 1 oct. 27, 1936. A. J. MAY

OPERATING CHAIR Filed Nov. 14, 1954 5 Sheets-Sheet 3 1N VEN] UR lam/ 6W@ BY %z'6 Afro EY Patented Oct.- 27, 1936 PATENT OFFICE Adam J. May, Rochester,

Dental Manufacturing Company, Inc.,

N. Y., signor to Ritter Rochester, N. Y., a corporation of Delaware Application November 14,

1934, Serial No. 753,003 i 9. Claims. (Cl. 155-25) The present invention relates to an operating chair and has for one object to provide an improved chair of this class embodying a simplified design having relatively few parts constructed and arranged to afford economies both in the manufacture and operation of the chair.

A further object of the invention is to provide in a dental or other operating chair, 'improved means by which the extent of movement of one or more seat'supporting elements of the chair may be increased without increasing the height of the base relative to which said elements are f mounted for movement.

A further objectof the invention is to provide in a chair base having a vertically movable seat carrying section, improved' adjustable guide means `forr the section.

A further object of the invention is to provide in a chair of the class describedv having a hydraulically operated lifting mechanism for one or more vertically movable chair raising sections, an improved manually operable device for relieving the pressure in the system to permit the chair to be lowered, in combination with automatic means for controlling the manually operable device to insure cushioning of the chair when approaching its lowermost position.

A further object of -the invention is to provide in an operating chair having a base and a movablechair section provided with elevating means including a uid pressure system, an improved arrangement of parts associated with the chair section and operating when thelatter approaches its limit of movement in one direction to auto- J matically relieve the pressure in the system.

E A further object of the invention is to provide in a chair of the class described having a hydraulically operated pressure system including a cylinder and a seat raising piston therein, improved Valve means for relieving thel pressure within the cylinder arranged for operation by means associated with the cylinder when the piston is moved to a predetermined position therein.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features'being pointed out in the claims at the end of the specification.

' In the drawings:

Fig. 1 is a sectional elevation of a chair base embodying one form of the invention and showing the movable seat supporting section at its lowermost position;

Fig. Zis a similar view showing the seat sup- 'erating means for the pressure porting section at substantially its uppermost position;

Fig. 3 is a detailed sectional elevation showing the manner of supporting one of the guide members for the seat carrying section;

Fig. 4 is a perspective viewillustrating the construction of the lower end of the seat carrying section;

Fig. 5 is a detailed view illustrating one end of an eccentrically arranged supporting rod for the guide member shown in Fig. 3;

Fig. 6 is a horizontal section through the chair base'taken substantially. on line 6--6 lof Fig. 9;

Fig. 'I is a. fragmentary sectional elevation through the pressure relief valve operated by the chair carrying section when approaching its lowermost position;

Fig. 8 is a vertical section on line 8-8 of Fig.

'Z drawn to an enlarged scale and showing the valve in open position; Fig. 9 is a sectional elevation through the chair showing a cylinder and piston arrangement for lifting the chair supporting section Iand the oprelief valve actuated by said section;

Fig. 10 is an enlarged vfragmentary sectional elevation through the piston showing a second .relief valve in closed position;

Fig. 11 is a fragmentary sectional elevation taken through the upper end of the cylinder with the piston therein showing the valve moved to open position by a part on the cylinder, and

Fig. 12 is afragmentary sectional elevation taken on line I2--l2 of Fig. 11.

The same reference numerals throughout the several .views indicate the same parts.

In illustrating the present embodiment of the invention I have shown a base or pedestal, indicated generally by the reference character I0 and comprising the upper, lower, and intermediate frames or sections Il, i2 and i3, respec tively. Movable vertically within the base is a seat carrying section I4, on the upper end of which is mounted a support l5 for the seat or chair proper, not shown, said section being guided in its up and down movements by a collar or bushing i6 forming a closure for the section il of the base, as shown in Figs. 1 and 2.

A hydraulic pressure system is provided for operating the chair supporting sectionit, including a cylinder I1 having a piston therein comprising a head i8 and a stem I9 projecting through a, closure 20 on the cylinder and engaging the bottom of the seat support i5. The lower end of the cylinder is secured within a spider or frame 2I mounted on the bottom of the intermediate section I3 of the base,as best shown in Figs. 6 and 9. Clearance between the spider and the lower end of the seat supporting section I4 is alforded by slotting the latter as shown at I4a in Fig. 4.

Associated with the spider is a pump of any suitable design, for producing pressure within the system vto eiect elevation of the piston within the cylinder. The pump includes a base 22 carrying a cylinder 23 having therein' a plunger 24 operated in one direction by a spring 25 and in the opposite direction by an overlying member 26. The member 26 is pivotally supported within the forked end 21 o'f a pin 28 suitably connectedl with a shaft 29 which is journalled vin the wall ofy the base section II, the shaft' carrying an operating lever .30 disposed at one side of the chair base in position to be conveniently de-l pressed by the foot of the operator when it is desired to operate the pump.

The cylinder of the pump is provided with the usual automatic intake and outlet valves, not shown, the former of which opens on the upstroke of thevplunger 24 to admit oil to the lcylinder from the supply in the bottom of the base section I3, the approximate level of which is indicated by the dotted line 3I in Fig. 9.

The outlet valve is opened upon downward movement of the plunger to force the liquid into the passage 32 of the spider and into the lower` end of the cylinder I1 beneath the piston I 8 to elevate the latter and the stern I 9 thereon whereby to elevate the seat supporting section I4.

The piston I8 isnprovided with an improved valve arrangement for automatically relieving the pressure in the cylinder when the piston approaches its uppermost ,position therein as indicated in Figs. 11 and 12. In this arrangement the lower end of the piston stem is extended through the piston head andis provided with a longitudinally extending bore 33 forming a liquid outlet or discharge passage for relieving the pressure in the cylinder, produced by operation of the pump to effect elevation of the seat supporting section I4.

At the upper end of the bore the piston stem is provided with oppositely disposed elongated openings 34 communicating with the bore and forming outlet passages for the liquid discharging through the bore whereby the liquid is permitted to escape into the space between the piston head and the cap or closure 20 of the cylinder and also to the outside of the cylinder by way of the opening 35 formed in the cap through which the piston stem projects, the opening being made slightly larger-than the diameter of the stem. The valve for closing the passage 33 or bore of the stem comprises a beveled head 36 having a reduced extension I31 which is disposed Within and which is of less diameter than the bore, as shown in Fig. 12, the valve being held in closed position, as shown in` Fig. 10, by the pressure of the liquid within the cylinder during the pumping operations.

The valve extension 31 is provided adjacent its upper end with a transversely extending pin 38, the opposite ends of which are projected through the elongated openings 34 of the piston stem, said ends moving into engagement with the cap 20 or other suitable part on the cylinder'to move the valve downwardly to the open position shown in Fig. 12 when the piston approaches the upper end of the cylinder. In this position of the valve,

should operation of the pump be continued, the oilv or liquid within the cylinder will be forced out through the bore of the piston stem and the openings 34 and 35, from which it will ow downwardly to the oil reservoir in the bottom of the base section I3.

Improved means is also provided for manually releasing and .controlling the discharge of the supporting column of liquid in the cylinder to eiectlowering of the chair from various elevated positions. To this end the discharge port 32a of the spider leads from the cylinder I1 to the interior of a plug 39 screwed into the spider and recessed to form a valve housing as shown in Figs. 7 and 8. The plug has a reduced extension 40 projecting within the bore 4I of an upstanding member 42 formed on the spider. The plug is provided with upper and lower liquid discharge passages 43 and 44, the former being of smaller diameter than the latter and having one or more outlet ports 45 communicating with an annular passage l46 formed in the extension 40 of the plug and being free to discharge the liquid through an aperture 41 formed in the wall of the upstanding member 42, as shown in Fig. 8. The relief valve 48 is normally held in closing position relative to the discharge passage 44 by a spring 49 seated within the closure 5U screwed into the spider beneath the plug 39.

The valve 48 is provided with a stem, the upper end 5I of which is guided by the extension 40 of the plug and normally projects above the extension as shown in Fig. '7. The valve stem is reduced in diameter at 52 and is still further reduced at 53 to provide for a gradual escape of the oil from the liquid supporting column when the chair is being lowered. When the valve is initially opened, the larger portion 52 of the stem projects within the bore 43 of the plug and considerably restricts the outflow of the liquid. However as the valve stem is moved downwardly the portion 52 thereof will move out of the passage 43 so that the capacity of the latter will be slightly increased, thus permitting of an increase in the discharge of the liquid from the spider.

'I'he operating means for the valve preferably comprises a plunger 54 having a reduced lower end 55 extending within the bore 4I of the upstanding member 42 and normally held slightly spaced from the upper end of the valve stem by a spring'56 seated within a recessed portion of the member'I 42 and surrounding the portion 55 of the plunger, as shown in Fig. 7. The upper end ofthe plunger 54 is pivotally connected at 51 to an arm 58 on a rocker 59 secured on the inner end of an arbor 60 journaled in a bearing 6I formed in the wall of the section II of the base, as shown in Fig. 6. The arbor and the rocker are operated by a foot lever 62 to depress the plunger when it is desired to lower the chair by opening the relief valve 48 for the escape of the supporting column of liquid from the cylinderI1. It will be understood that the spring 56 will returnthe plunger 54 to .normal position when the operator removes his foot from the lever 62, at which time the valve 48 will be automatically closed by the spring 49, thus providing for thc stopping of the descending chair at various positions by checking the flow of the liquid from the cylinder I1.

Improved means is provided to insure cushioning of the seat supporting section when approaching its limit of movement in a downward direction by operating to condition the spring pressed re-` Cil lief valve, which controls the discharge of the supporting column of liquid, for return to closing position in time to trapsuicient liquid in the bottom of the cylinder to insure the desired cushioning effect. This means is associated with the foot lever 62 and parts controlled thereby for Vmanually operating the relief valve 48 and will overcome the resistance of the .pressure produced by the operator on the foot lever should he fail to release the latter when the chair approaches its lowermost position. To vthis end the rocker 59, controlled by the foot lever |52,` is provided with a shortv arm orprojection 63 pivotally connected with which is a depending` operating member 64 having a laterally projecting foot 65 at its lower end for engagement by a lug 66 on the seat supporting` section I4 when 4the'latter ap proa'ches its limit of movement in a downward direction whereby the rocker 59 will be positively 4operated to lift the plunger 54 in order'to release the valve 48 for return to closing position by the spring 49 to prevent further escape of the liquid from the bottom of the cylinder through the passage 32a of the spider` .Heretofore in chairs of the present type, it has been customary to provide upstanding guide rods or the like Within the chairbase for guiding a movable section of the chair therein. With this arrangement the rods are supported at their ends by inwardly extending parts onthe wall of the base while the movable chair section is provided with projecting lugs apertured to receive the rods and designed for movement thereon between said inwardly extending parts; With this construction the extent of movement of the chair section within the base has been considerably reducedv by l reason of the limitation of movement of the lugs by the inwardly extendingsupporting parts for the rods carried by the base. Thus the extent of movement of the chair supporting section has not only been limited in an upward direction, but in a downwardv direction as` Well, and since it is highly desirable to at times adjust the chair both to relatively high and low positions it is important to provide a construction which will permit of an increase in the extent of movement of the chair in either direction which has'been done in the present design Without increasing the height of the base or the cost of constructing the chair. In this arrangement the members for guiding the chair section are also made. adjustable-to `better accommodate vthem to the parts on the section which engage or move on the guiding members.

As shownin Figs. 1 to 3, inclusive, the section ll of the base is provided with oppositely disposed sets OsuppOrtingmemberS, each set including an upper member 61 extending inwardly from the base section Il and likewise each set including a lower member 68 also extending inwardly from said base section.4 The members 61 and 68 of each setare formed integrally with the base section, although they may be separately constructed in any preferred manner and` applied to said base section by any suitable means. In

the present arrangement the members of each set are provided with substantially alined bores for receiving the-reduced upper and lower ends 69 and 1,0 of the rods 1I. The reduced ends 69 and are eccentrically disposed with respect to the axis of the rod to permit of adjustment of the latter by rotation for a purpose which will appear hereinafter. The bore or opening in the lower lug 68 is preferably made slightly larger in diameter than the rod so thatv the latter may be convenently inserted therethrough While applying it to the base section Il., at which time 'it is also passed through a cylindrical tubular guide member 12, the upper and lower ends of which are preferably seated on the members 61 and 68. The lower end 10 of the rod extends within a collar 13 tted within the bore of the member 68 and is held in position by a set screw 14 which extends through the wall of the collar and engages the end 10 of therod to hold the latter and the tubular member 12 at the desired position of adjustment. The seat or chair supporting section I4 is provided at its lower end with oppositely disposed portions 15 which are preferably inthe formA of lugs, recessed at 16 to receive the tubular guide members'12, and which afford spaced portions 15a extending at opposite sides of the tubular member 12 as shownin Fig.I 6, the recesses being semi-circular and of a size toy closely t said tubularfmembers. Adjustment' of the rod and tubular. member thereon is preferably effected by the use of a suitable tool inserted within the slot 11 of the reduced end 10 of the ro'd and operated to turn' the rod and the tubular member in the required direction either to properly position said Y,

1 member within the recess 16 when assembling the parts, or to subsequently take up for wear between said recessed portion and-the tubular member.

Thus by the use of the open endedA lugs or recessed portions 15 on the seat supporting section i4 interference between said lugs and the members 61 and 68 on the base Il will be avoided when moving the seat supporting section to either of the positions shown in Figs. 1 and 2. With this arrangement an increase in the extent of movement of the section is afforded without increasing the height' of the base. In other words, the entire distance between the top and bottom portionsof the base is utilized for movement of the section. This is advant-ageous Afor the reason that it permits the seat to be adjusted either to a higher or a lower position with respect to the base that it has been possible to move it in previous chairs of this type.

In the present construction, although only one movable chair carrying section has been shown, it will be understood that the improvements 'described and claimed herein can readily be made use of in-a chair having a plurality of extensible sections, whether telescopically or otherwise arranged.

1. In a chair having a-base and a seat, the combination of a seat supporting section movable vertically within the base and on which lthe seat is mounted. said supporting section having a laterally projecting recessed portion adjacent its lower end, Ia vertically disposed guide for 2. In a chair having"a base' and a seat, the

lmeansfor moving said section-within the base.

CTI

combination of a seat vsupporting section movable vertically within the base, and on which the seat is mounted, oppositely disposed guides for said section arranged vertically within the base in spaced relation to the body of said section, upper and lowerv supporting members for each of said guides xed to the wall of the base and extending inwardly therefrom, said seat supporting section having laterally projecting recessed lugsat opposite sides thereof adjacent the bottom of the section, said guides engaging said lugs within the recesses thereof to guide said` section within the base, parts of each of said lugs moving past one of said supporting members when the said supporting section approaches either of its limits of movement within the base whereby to increase the extent of movement of the section in opposite directions within the base, and means for moving said section within the base.

3. Guiding' means for guiding the seat supporting section of a chair in its vertical movements on a chair base, said means comprising oppositely disposed recessed portions projecting laterally from the supporting section adjacent its lower end, guides for said section extending vertically within the base in spaced relation to said section, said recessed portions receiving saidguides and moving thereon when moving the section within the base, upper and lower supporting lugs for each guide projecting laterally from the base adjacent the opposite ends thereof', the supporting lugs at one end of the base extending within .the laterally projecting re cessed portions of said section when the latter is moved in one direction t'o a predetermined position and the supporting lugs at the opposite end of the base extending within said recessed projecting portions when the section is moved in an opposite direction to a different predetermined position, andfmeans for moving the section within the base to saidpredetermined positions.

4. VGuiding means for guiding the seat sup- .porting section of a chair in its vertical movements on a chair base, said means comprising vertically extending cylindrical guides eccentrically lmounted within the base, said seat supporting section having oppositely disposed recessed portions for receiving said guides, said guides being rotatably adjustable to accommodate them to said recessed portions, and means for moving said seat supporting section upon said guides.

5. Guiding means for guiding the seat supporting section of a chair in its vertical movements on la hollow chair base, said means comprising oppositely disposed sets of upper` and lower supporting members in the base, a vertically arranged cylindrical guide eccentrically mounted in each of said sets of supporting members, said seat supporting section having recessed portions corresponding to and receiving said guides, said guides being rotatably adjustable to accommodatethem to said recessed portions, said recessed portions each moving partly past portions of the supporting members corresponding thereto, when theV seat supporting section approaches said limits of movement, and means for moving said seat supporting section within the base.

6. Guiding means for guiding the seat supporting section of a chair in its vertical movements on a hollow base, said means comprising a transversely extending member for guiding the seat supporting section, a vertically extending cylindrical guide eccentrically mounted within the base, said seat supporting section having a recessed portion for receiving said cylindrical guide, the latter cooperating with said transversely extending member to guide the seat supporting section in its up and down movements, said cylindrical guide being rotatably adjustable to accommodate it to the recessed portion of said seat supporting section, and means for moving said seat supporting section within the base.

7. Guiding means for guiding the seat supporting section of a chair in its vertical movements on a hollow base, said means comprising a transversely extending wall through which the supporting section extends and is guided, upper and lower supporting members on said hollow base, a vertically arranged cylindrical guideeccentrically mounted in said supporting members, and a recessed portion on said seat supporting section for receiving said cylindrical guide, said guide cooperating with said recessed portion and said wall to guide said section in its up and down movements, and being rotatably adjustable to accommodate it to the recessed portion of said seat supporting section by turning it in one direction.

8. Guiding means for guiding the seat supporting section of a chair in its vertical movements on a base, said means comprising upper and lower supporting members on the base prof vided with oppositely disposed bores, a rod extending between said members and having' eccentrically disposed end portions extending within said bores, one of said bores being of a larger diameter than that of the rod and having a collar surrounding the end of the rod extending therein and in which the end of the rod h as a bearing, a sleeve extending between said supporting members and within which said rod is disposed, said seat supporting section having a recessed portion for receiving said sleeve,. the latter forming a guide for said section, said rod being rotatable to eccentricallyadjust it and said sleeve to accommodate the latter to the recessed portion of said seat supporting section, and means for holding said rod in adjusted position, release of said `means permitting the collar to be removed and the rod to be withdrawn through the opening of the supporting member in which the collar is mounted.

9. A hydraulic system for operating a chair having a base and a seat supporting section, a spring actuated valve for relieving pressure within the system, said valve having a vertically disposed operating stem, a plunger coaxial with the stem, resilient means normally holding the plunger in spaced relation to the stem, a rocker pivoted on'the base and pivotally connected with said plunger, a manually operable member for actuating the rocker to move the plunger into engagement with the valve stem to eiect opening of the valve a rod pivotally connected with and depending from the rocker in substantially paralle] relation to saidplunger, and a part on the seat supporting section adjacent the bottom thereof for engaging the rod when the section approaches its lowermost position to overcome the resistance of the manually operable member when held at operating position, and to move the plunger from valve operating position to inoperative position.

ADAM J. MAY. 

